The Lake Kushaqua dam, which impounds both Kushaqua and Rainbow lakes, is being raised to better accommodate high-water events. (Enterprise photo — Justin A. Levine)

ONCHIOTA — The Lake Kushaqua dam, which impounds Kushaqua and Rainbow lakes as well as the Rainbow Narrows, is currently being raised after nearly a decade of planning.

The dam, which is just off Kushaqua-Mud Pond Road near Onchiota, will be nearly 3 feet higher when work is completed. The contractor for the project said the work on the dam itself should be completed by the end of November, and some decking will be installed early next year to finish the project.

“We’re raising the whole dam and the berm around it like 2.8 feet, just to stop the water from ever washing the dam out,” said Ray Lobdell of Northeast Concrete Pouring and Cutting Inc. “We should be done — weather permitting — in like three weeks to a month. And then we have to come back to change the stop blocks in the spring.”

Kushaqua-Mud Pond Road is maintained seasonally, so Lobdell said as long as there are no big snowstorms, the work should remain on track this fall.

Roger Gorham, who is chair of the Rainbow Lake Water Protection District and lives in Rainbow Lake, said ownership of the dam is a little complicated but that Franklin County owns it, although the protection district oversees it.

“The Rainbow Lake Association took control of the dam and Franklin County created the Rainbow Lake Protection District to monitor the dam and make sure it’s operating effectively,” he explained. “The Rainbow Lake Association arranged for this (work) to occur, but the Rainbow Lake Protection District is responsible for the dam.”

He said the county had to approve the work, but the protection district is a taxing agency and is paying for the work. Gorham said the contract is for $211,000, paid for through taxes on about 200 shoreowners. Rainbow Lake flows into the Narrows, which then flow into Lake Kushaqua. Once the water spills over the dam, it is a continuation of the North Branch of the Saranac River.

“The Narrows and Rainbow Lake itself, all the property owners are part of this taxing district,” he said. “So it’s Franklin County that will pay, but it’s only members of this water protection district who actually support — through taxes — the funding.”

There are only a couple of private lots on Lake Kushaqua as most of the shoreline is owned by the state, including the Department of Environmental Conservation’s Buck Pond Campground, but Rainbow Lake and the Narrows are dotted with private homes and camps.

Gorham said the need to improve the dam came after high water in the spring of 2011, when much of the North Country experienced severe flooding.

“We had a real high-water event at that time, and it came up high enough that the dam wasn’t in jeopardy, but the concern was that the earth on either side of the dam could be breached,” he said, “which would ruin the dam.

“We’ve been working since then, with the DEC primarily, to determine what is the best solution to address the problem. The DEC’s dam safety unit eventually approved a plan, which is what is going on now.”

Gorham said the work, when boiled down, will raise the dam while increasing the protection district’s ability to accommodate future high-water events.

“They’re building up the berm on either side of the entrance to the dam, so that if there is a high-water event, the berms will keep the water from breaching on either side of the dam,” he said. “In addition, they are building up the concrete on the surface of the dam.

“It’s to the point where it should protect against any conceivable high-water event that we might experience.”

Gorham said that additionally, there will be new flash boards installed on the dam which will allow for finer control of the lake level. He said the lake will remain as its always been — higher in the spring and lower in the summer and fall — but that increased control will help in flood events.

“That way, in a high-water event, we have the ability to raise these flash boards so that more water can flow over the dam more quickly,” he said. “And we’re improving that system. There are three sections on top of the dam, and now all three will have flash boards that can be raised up.”

Currently only two of the three sections have flash boards in them. Lobdell said the current wooden boards will be replaced with aluminum ones in the spring.

“We’re not changing the lake level; the dam was never designed to control the level of the lake,” Gorham continued, noting that the dam was originally built to generate hydroelectricity. “Mother Nature is going to do that. The dam can’t control that, other than these flash boards can allow us to respond to whatever Mother Nature sends us.

“In the spring when you’ve got a lot of rain and snow runoff, the water level is going to rise, and in some cases people’s boathouses are going to flood, as they have for years. And that’s not going to change other than we can address it more quickly.”